Filesystem consistency check and interactive repair. Journaling file systems avoid the need to run fsck.
Syntax
fsck [options] [filesystem] ...
Options
-- Pass all subsequent options to filesystem-specific checker.
All options that fsck doesn’t recognize will also be passed.
-r Interactive mode; prompt before making any repairs.
-s Serial mode.
-t fstype
Specify the filesystem type. Do not check filesystems of any other type.
-A Check all filesystems listed in /etc/fstab.
-N Suppress normal execution; just display what would be done.
-R Meaningful only with -A: check all filesystems listed in /etc/fstab except the root filesystem.
-T Suppress printing of title.
-V Verbose mode.
EXIT CODES
1 Errors were found and corrected.
2 Reboot suggested.
4 Errors were found but not corrected.
8 fsck encountered an operational error.
16 fsck was called incorrectly.
128 A shared library error was detected.
The return status is the exit status of the last command executed in consequent-commands, or zero if none were executed.
Dennis Ritchie: “So fsck was originally called something else”
Question: “What was it called?”
Dennis Ritchie: "Well, the second letter was different” ~ Q&A at Usenix
reboot - Reboot the machine.
ext2 File System (non journaling).
ext3 File System - Red Hat Journaling File System.
ddrescue - Data recovery tool.
Equivalent Windows command:
CHKDSK - Check Disk - check and repair disk problems.